Early Levothyroxine Post Radioactive Iodine

October 11, 2019 updated by: Marius Stan, Mayo Clinic

Prevention of Overt Hypothyroidism Following Radioactive Iodine Therapy for Graves' Disease

The study will try to answer the question of whether early treatment with levothyroxine at 4 weeks after radioactive iodine for Graves'disease will prevent overt hypothyroidism (low thyroid hormone levels).

Study Overview

Status

Completed

Conditions

Study Type

Interventional

Enrollment (Actual)

61

Phase

  • Phase 2
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic in Rochester

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion criteria:

-all adult patients (ages 18-70 years) with Graves' Disease (GD) who will receive radioactive iodine (RAI) ablation of the thyroid gland for treatment of GD

Exclusion criteria:

  • clinically manifest Graves' ophthalmopathy (GO)
  • recent (<1 yr.) history of arrhythmias or any history of ventricular arrhythmias
  • preexistent cardiomyopathy
  • malnutrition
  • psychiatric history that could get worse if patient remains persistently hyperthyroid
  • unlikely to return for the planned follow-up visits
  • unlikely to comply with the blood drawing schedule
  • unlikely to complete the hypothyroid-Health Related Quality of Life (HDQL) and Thyroid Specific (TSQ) questionnaires

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Levothyroxine
In the intervention arm patients will start levothyroxine therapy at 4 weeks after RAI therapy. The initial dose of levothyroxine will be 25 mcg/day. It will be increased to 50 mcg/day 2 weeks later and then adjusted at 8 weeks post RAI based on a full face-to-face clinical and biochemical evaluation.
Early initiation of levothyroxine after radioactive iodine (to start at 4 weeks).
Other Names:
  • Thyroid hormone
Placebo Comparator: Placebo
In the control arm patients will receive placebo capsules and be evaluated for levothyroxine therapy during a full face-to-face evaluation at 8 weeks.
Placebo to start at 4 weeks after RAI

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With Overt Hypothyroidism
Time Frame: 8 weeks
Incidence of overt hypothyroidism at 8 weeks post radioactive iodine treatment (RAI). Overt hypothyroidism was defined as thyroid stimulating hormone (TSH) test result > 3.0 milliunits per liter (mIU/L) or thyroid hormone free T4 (fT4) < 0.8 nanograms per deciliter (ng/dL). Free T4 is the portion of total T4 thyroid hormone that is available to your tissues in your bloodstream.
8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Hypothyroid-Health Related Quality of Life
Time Frame: 4 weeks, 8 weeks
The mean change in Quality of life scores was measured by the Hypothyroid-Health Related Quality of Life (HRQL) questionnaire. This questionnaire consists of 27 questions specifying the severity of the discomfort or symptoms of hypothyroidism using a 5 point scale for each question with "not at all"=1 to "all the time"=5. Higher scores are associated with a lower quality of life. The change between weeks 4 and 8 were assessed using a hierarchical linear model. The primary parameter of interest from the model was the treatment by time interaction term. Time was a collection of indicator values representing each assessment point.
4 weeks, 8 weeks
Change in Thyroid Specific Quality of Life
Time Frame: 4 weeks, 8 weeks
The mean change in quality of life scores was measured by the Thyroid Specific Questionnaire (TSQ). This questionnaire consists of 12 questions ranked on a four-point scale for each question where 0 is 'better than usual' and 3 is 'much less than usual'. A higher score indicates higher levels of dissatisfaction and a lower quality of life. The change between weeks 4 and 8 were assessed using a hierarchical linear model. The primary parameter of interest from the model was the treatment by time interaction term. Time was a collection of indicator values representing each assessment point.
4 weeks, 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Marius Stan, MD, Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2013

Primary Completion (Actual)

April 1, 2017

Study Completion (Actual)

April 1, 2017

Study Registration Dates

First Submitted

September 23, 2013

First Submitted That Met QC Criteria

September 23, 2013

First Posted (Estimate)

September 25, 2013

Study Record Updates

Last Update Posted (Actual)

October 29, 2019

Last Update Submitted That Met QC Criteria

October 11, 2019

Last Verified

October 1, 2019

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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